Spontaneous intraperitoneal expulsion of an unruptured hydatid cyst.

We report a 43-year-old man with a 20 x 20 cm hydatid cyst, spontaneously extruded out from the left lobe of the liver. This complication of hydatid cyst has not been recorded earlier, and makes the case unique in itself and worth reporting. The patient presented with a rare complication of biliary peritonitis of hydatid disease.